1. Technical Field
The present invention relates to an image forming apparatus including a determination device which determines the degree of deterioration of a latent image carrier on the basis of the result of detection of the surface potential of the latent image carrier.
2. Related Art
In an image forming apparatus which forms an image through an electrophotographic process, a surface of a latent image carrier is uniformly charged by a charging device such as a corona charger, and a latent image having an electric potential different from the uniformly charged potential is written on the latent image carrier by, for example, optical scanning. Then, the latent image is developed by a development device with toner selectively adhering to the latent image on the latent image carrier. The thus-obtained toner image is transferred to a recording sheet (i.e., recording medium) directly or via an intermediate transfer member. Thereby, a recording sheet having the toner image formed thereon is obtained. After the transfer of the toner image, residual charge on the latent image carrier is removed by a discharging device, and the latent image carrier is again uniformly charged by the charging device to prepare for the next latent image formation.
In the configuration which performs such an electrophotographic process, the charging performance of the latent image carrier is gradually degraded by repeated uniform charging, latent image writing, and discharging performed on the latent image carrier. It is difficult to form a latent image with a stable potential on the latent image carrier substantially degraded in charging performance, and thus to maintain normal image quality.
Therefore, the image forming apparatus may be configured to, immediately after the surface of the rotatable drum-shaped latent image carrier is uniformly charged by the charging device, detect the uniformly charged potential by using a potential sensor, and, if the result of detection falls below a predetermined threshold value, determine that the latent image carrier has deteriorated significantly and prompt a user to replace the latent image carrier. Thereby, the user is prompted to replace the latent image carrier before the latent image carrier deteriorates too much to form a latent image with a stable potential. Accordingly, image deterioration due to the deterioration of the latent image carrier is minimized